1. Field of the Invention
The present invention relates to an optical module, in particular, the invention relates to an optical module having a plurality of optical signal sources and outputting a multiplexed optical signal that multiplexes optical signals each emitted from respective optical signal sources.
2. Related Background Arts
The transmission quantity to be transmitted by a single fiber has been expanding year after year. The transmission capacity per a fiber has become 40 Gbps, 100 Gbps, or higher in the Metro/Access Network System. The wavelength division multiplexing (WDM) has been known as one of key technologies to enhance the transmission capacity. The WDM system multiplexes a plurality of optical signals each attributed to a wavelength different from others. According to a draft of the LAN-WDM standard, which is now drawing; four optical signals each having a transmission speed per a wavelength of 25 Gbps and a span of 800 GHz are multiplexed to realize the transmission capacity of 100 Gbps. The wavelengths of respective optical signals are 1295.56, 1300.05, 1304.58 and 1309.14 nm. An optical transceiver ruled in the LAN-WDM draft has outer dimensions following a multi-source agreement (MSA) of the CFP (100 G form factor pluggable). However, further downsizing of the optical transceiver is strongly requested to install optical transceivers in high-density within a communication apparatus.